1. Field of the Invention
The present invention relates to a functional polyolefinic film. In more detail, it relates to a polyolefinic film, or a tubular film applied in corona discharge treatment at a high voltage current, which has not been proposed conventionally, and manufacturing method thereof, and bags for packaging, adhesive sheet and adhesive tape manufactured from their films.
2. Description of the Prior Art
In general, paper is opaque and weak against water, and also in mechanical strength but quite low in cost, hygroscopic, superior in touching, air permeability, moisture permeability, adhesive property, writing property and printing property and so on, in addition, easy to be torn by hand and good to recover as base material (hereinafter referred as "recoverability") and to be disposed (hereinafter referred as "disposability"), so that a large amount of paper has been used. On the other hand, polyolefinic film is superior in transparency, mechanical strength and water resistance, comparatively low in cost, and so that a large amount of the film is used also in a various fields, but not soft in touch, inferior in air permeability, moisture permeability and adhesive property and not easy to be torn by hand like in case of paper and inferior in base material recoverability and disposalability. That is, there have not existed such polyolefinic film such as having water resistance and being superior in touch, air permeability, moisture permeability, writing property and printing property. If such film as a polyolefinic film which has such properties of paper is developed, it can be not only for replacement with paper but also for a widely new use, in which a tearing property is needed but paper is not used therefor due to low water resistance.
The object of the present invention is to provide the functional polyolefinic film or tubular film, which have not been proposed conventionally, being superior in touch, air permeability, moisture permeability, printing property, writing property and adhesive property like in paper, and easy to be torn by hand, resistance for water and chemicals, which means not broken with water and not deteriorated by being in contact with such as acid or alkali and good for disposability, and manufacturing method thereof and the products in which such materials are used.
The present inventor has completed the invention relating to the manufacturing technique by applying a corona discharge on the inner surface of the polyolefinic tubular film to make a masking film, filed a patent application thereof and obtained a Japanese Patent under the number of 2,514,899. On the other hand, when developing this technique of the patent, he has found an outstanding result for solving the above conventional problems in case a specific condition of the corona discharge is applied and continued to study this technique and completed the present invention.